#include <REGX52.H>

void Delaylms(unsigned int xms)
{
	unsigned char i,j;
	while(xms)
	{
		i=2;
		j=239;
		do{
			while(--j);
		}while(--i);
		xms--;
	}
}

void main()
{
	
	while(1)
	{
		P2=0xFE;	//1111 1110
		Delaylms(500);
		P2=0xFD;	//1111 1101
		Delaylms(500);
		P2=0xFB;	//1111 1011
		Delaylms(500);
		P2=0xF7;	//1111 0111
		Delaylms(500);
		P2=0xEF;	//1110 1111
		Delaylms(500);
		P2=0xDF;	//1101 1111
		Delaylms(500);
		P2=0xBF;	//1011 1111
		Delaylms(500);
		P2=0x7F;	//0111 1111
		Delaylms(500);
	}
}